package 题目集.数学;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.math.BigInteger;
import java.util.StringTokenizer;

public class 机器人繁殖 {
    public static void main(String[] args) {
        BigInteger _2 = new BigInteger("2");
        Reader sc = new Reader();
        int n = sc.nextInt();
        BigInteger sn = sc.nextBigInt();
        BigInteger res = (sn.add(_2.pow(n + 1))).subtract(_2).subtract(new BigInteger(n + ""))
                .divide(_2.pow(n + 1).subtract(BigInteger.ONE));
        System.out.println(res);
    }

    static class Reader {
        private BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        private StringTokenizer tokenizer = new StringTokenizer("");

        private String innerNextLine() {
            try {
                return reader.readLine();
            } catch (IOException ex) {
                return null;
            }
        }

        public boolean hasNext() {
            while (!tokenizer.hasMoreTokens()) {    //内存中没有
                String nextLine = innerNextLine();
                if (nextLine == null) {     //且没有下一行
                    return false;
                }
                tokenizer = new StringTokenizer(nextLine);  //读入一行
            }
            return true;
        }

        public String nextLine() {
            tokenizer = new StringTokenizer("");    //清空内存中的字符
            return innerNextLine();
        }

        public void clear() {
            tokenizer = new StringTokenizer("");
        }

        public String next() {
            hasNext();
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

        public double nextDouble() {
            return Double.parseDouble(next());
        }

        public BigInteger nextBigInt() {
            return new BigInteger(next());
        }
    }

}
